The present invention relates to the field of computer technologies, and in particular, to a method and an apparatus for detecting ambient light brightness.
With the development of projection device technologies, projection devices are used in a growing number of places. Especially after the emergence of micro projection devices, because of a small size, portability, and low power consumption of the micro projection devices, a growing number of people accept the micro projection devices. However, a biggest defect of the micro projection devices is that projection flow brightness is unsatisfactory, and ambient light brightness greatly affects a projection image effect; for example, existence of light sources such as natural light and lamplight greatly affects projection image quality of a projection device. Therefore, a technology that can dynamically change local brightness of an image according to an ambient light parameter and image content to enhance image contrast, so that a projected image is clearer, is desirable in the art. However, use of the technology depends on accurate detection of the ambient light brightness, and inaccurate ambient light brightness detection inevitably makes the image algorithm become invalid. Therefore, solving a problem of how to accurately detect ambient light brightness becomes a difficult problem.
In the prior art, a result of ambient light brightness may generally be obtained by using an optical sensor to acquire a light sensing value from a direction in which ambient light needs to be detected. However, if ambient light brightness is detected when a projection device projects an image, what a light sensing component senses is not only ambient light brightness, but also the light from the projected image when the projection device operates; moreover, brightness of the projected image may be higher than actual ambient light brightness. In this case, the optical sensor obtains an ambient light value that includes brightness of the image projected by the projection device, instead of real ambient light brightness.